A research team led by Prof. Zang (College of Chemistry, Zhengzhou University) report two silver-based bimetallic clusters with atomically precise structures, Ag 14 Pd and Ag 13 Au 5 . By introducing Pd and Au atoms into the silver clusters, the charge polarization of the active sites on the cluster catalysts can be effectively modulated, thereby altering the product distribution and ultimately increasing the Faradaic efficiency (FE) and yield of urea.
In a GDE-based flow cell under ambient conditions, the Ag 14 Pd cluster is more favorable for the NO 3 RR, while the Ag 13 Au 5 cluster is more inclined towards CO 2 RR. The urea formation rate on Ag 14 Pd and Ag 13 Au 5 clusters at their highest FEs are 143.3 and 82.3 mg h -1 g cat -1 , respectively.
Experimental and density functional theory (DFT) results confirmed that *NH 2 and *CO are the most probable C–N coupling intermediates. The charge transfer between the metal active sites occurs by introducing heterometallic atoms into the silver clusters. The difference in the adsorption energy of the two clusters on the reaction intermediates during the electrocatalytic synthesis of urea affects the energy barrier of the C–N coupling reaction process, which leads to a significant difference in the performance of the two in the electrocatalytic synthesis of urea. The effect of charge polarization of the catalyst active center induced by doping with heterometallic atoms on the selectivity of electrocatalytic urea synthesis was verified.
These findings not only provide a set of effective strategies for designing and obtaining ideal bimetallic catalysts, but also lay a solid foundation for further elucidation of the relationship between the structure and catalytic activity of silver-based bimetallic catalysts, and provide a new possibility for the development of advanced cluster catalysts for urea synthesis.
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See the article:
Charge polarization of silver-based bimetallic clusters regulates the performance of electrocatalytic urea synthesis
https://doi.org/10.1093/nsr/nwae440
National Science Review